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Groups > sci.physics.relativity > #432886 > unrolled thread
| Started by | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| First post | 2017-09-19 14:56 +0200 |
| Last post | 2017-09-24 06:48 -0700 |
| Articles | 20 on this page of 185 — 15 participants |
Back to article view | Back to sci.physics.relativity
Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-19 14:56 +0200
Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-19 06:00 -0700
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:48 +0000
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:53 +0000
Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-19 08:05 -0700
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 09:09 -0700
Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-19 09:35 -0700
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 10:45 -0700
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 22:01 +0000
Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-20 07:30 -0700
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-20 20:00 +0000
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 07:55 -0700
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:58 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-20 09:18 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-20 04:48 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-20 13:47 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-20 14:33 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:05 +1000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-20 16:07 -0700
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:24 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:22 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:28 +0200
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:40 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-29 09:20 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-29 08:49 +0200
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-29 12:08 +0000
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-29 05:59 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:22 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:08 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 20:30 -0700
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-20 20:42 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:39 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-21 02:18 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:25 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:37 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:34 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 13:30 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 06:44 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-10-10 00:24 +0200
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 03:02 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 06:50 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 22:23 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 10:08 +1000
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-23 04:09 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-23 13:32 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 09:02 +1000
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 06:31 -0700
Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-23 19:37 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 07:26 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 16:44 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 08:03 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 17:35 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:26 +1000
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 17:36 -0700
Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-24 18:24 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 07:34 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:49 +1000
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 07:56 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-25 00:00 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:47 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-25 00:47 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 23:53 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 19:53 +1000
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-25 02:58 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:54 +0200
Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:15 +1000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-25 10:19 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:56 +0200
Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:11 +1000
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 14:43 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 01:26 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 02:06 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-27 08:39 +1000
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:52 +0200
Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:18 +1000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-25 10:21 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:19 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:48 +1000
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 08:31 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 17:46 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-24 09:30 -0700
Re: Train gedanken - again. Paparios <mrios@ing.puc.cl> - 2017-09-24 08:04 -0700
Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-24 08:24 -0700
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-23 14:11 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 08:53 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 02:31 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 16:39 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 12:34 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:30 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 22:32 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 09:41 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-25 02:51 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:51 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-25 12:48 +0000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 11:13 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 02:31 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 02:34 -0700
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 03:25 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-19 22:40 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 08:08 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:46 +1000
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 08:33 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 00:04 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 00:34 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 00:42 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 10:54 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:49 +1000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-20 15:59 -0700
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:54 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:43 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 12:56 +0200
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-22 11:04 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:36 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 01:38 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-27 20:00 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:06 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:30 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:04 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 20:36 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 07:21 +0200
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-26 21:57 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 20:57 -0700
Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-26 21:00 -0700
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:24 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 17:39 -0700
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 02:52 +0200
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 10:48 +0200
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 15:13 +0200
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 20:19 +0200
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-20 20:02 +0000
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:10 +1000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 12:46 +0200
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-20 13:14 -0700
Re: Train gedanken - again. mitchrae3323@gmail.com - 2017-09-20 13:27 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:29 +1000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 14:03 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-21 05:19 -0700
Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-21 12:42 +0000
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-21 07:24 -0700
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 22:16 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:51 +1000
Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 03:02 +0000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-21 20:18 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 20:39 -0700
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-21 20:42 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 07:49 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 23:51 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 09:04 +0200
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 09:08 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-22 00:27 -0700
Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 11:52 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-22 04:05 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:46 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:26 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:31 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:01 +0200
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 20:22 -0700
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 12:00 +0200
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 14:08 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:41 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:28 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:32 +1000
Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:02 +0200
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-22 07:03 -0700
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 19:55 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:42 +1000
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-23 06:55 -0700
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-24 11:17 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:30 +1000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 13:52 +0200
Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-22 05:34 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 08:05 +1000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-23 15:38 +0200
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 09:12 +1000
Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-23 16:17 -0700
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-24 11:03 +0200
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 07:11 -0700
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 07:38 -0700
Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:43 +1000
Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-25 14:38 +0200
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 07:15 -0700
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 07:38 -0700
Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 04:20 +1000
Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 01:23 -0700
Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 06:48 -0700
Page 7 of 10 — ← Prev page 1 … 5 6 [7] 8 9 10 Next page →
| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-26 21:57 +0200 |
| Message-ID | <7391987.NyiUUSuA9g@PointedEars.de> |
| In reply to | #433293 |
gehan.ameresekere@gmail.com wrote: > […] Thomas 'PointedEars' Lahn wrote: >> HGW wrote: >> > On 20/09/17 18:54, Poutnik wrote: >> >> When saying A, you have to say B as well. >> >> >> >> The aether mentioned in GR context >> >> has nothing in common with luminoferous aether of aether theories. >> > >> > ...then why did Einstein say, "a universe without an aether is >> > unthinkable." >> >> Because he thought so. That does not mean that he was right. >> >> You see, contrary to popular belief, and the whinings of crackpots here, >> we (working in science and truly interested in science) now know that >> Einstein was *wrong* about *many* things, e.g. QM. > > That's ironic. You are saying that you who are "working in science and > truly interested in science" now know that Einstein was "wrong" yet when > "crackpots" claim that Einstein was wrong, they are crackpots. Maybe they > are talking about different things. You have not really taken the course, have you? PointedEars -- Q: Why is electricity so dangerous? A: It doesn't conduct itself. (from: WolframAlpha)
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| From | gehan.ameresekere@gmail.com |
|---|---|
| Date | 2017-09-26 20:57 -0700 |
| Message-ID | <25be2139-49f1-4f9c-a3f4-a4886861a752@googlegroups.com> |
| In reply to | #433944 |
On Wednesday, September 27, 2017 at 1:27:39 AM UTC+5:30, Thomas 'PointedEars' Lahn wrote: > > You have not really taken the course, have you? > > No, I have not. I have, however been following the first lecture on YouTube, and it is difficult to understand at the moment. Sitting down with a notebook and pencil and trying to figure out what he is saying would be one approach. http://www.youtube.com/watch?v=hbmf0bB38h0 No-one said this would be easy.
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| From | "Dono," <sa_ge@comcast.net> |
|---|---|
| Date | 2017-09-26 21:00 -0700 |
| Message-ID | <a069ce07-0e9f-41e1-8d72-5e9694280471@googlegroups.com> |
| In reply to | #434029 |
On Tuesday, September 26, 2017 at 8:57:17 PM UTC-7, gehan.am...@gmail.com wrote: > On Wednesday, September 27, 2017 at 1:27:39 AM UTC+5:30, Thomas 'PointedEars' Lahn wrote: > > > > You have not really taken the course, have you? > > > > > No, I have not. I have, however been following the first lecture on YouTube, and it is difficult to understand at the moment. Sitting down with a notebook and pencil and trying to figure out what he is saying would be one approach. > > http://www.youtube.com/watch?v=hbmf0bB38h0 > > No-one said this would be easy. Imbecile You cannot start with GR. You need to start with SR. Actually, in your case, you nee to start with 9-th grade kinematics.
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-27 15:24 +0200 |
| Message-ID | <2102696.NG923GbCHz@PointedEars.de> |
| In reply to | #434029 |
gehan.ameresekere@gmail.com wrote: ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Your real name belongs there. > On Wednesday, September 27, 2017 at 1:27:39 AM UTC+5:30, Thomas > 'PointedEars' Lahn wrote: Attribution *line*. >> You have not really taken the course, have you? > > No, I have not. I figured. It was almost evident by the crackpot nonsense that you posted. > I have, however been following the first lecture on YouTube, and it is > difficult to understand at the moment. Sitting down with a notebook and > pencil and trying to figure out what he is saying would be one approach. > > http://www.youtube.com/watch?v=hbmf0bB38h0 > > No-one said this would be easy. True, but it would be a lot easier if you took the online course on *special* relativity, *then* watched the lectures on *special* relativity, *before* you watch these lectures on *general* relativity. Taking shortcuts when studying is not going to work and will only cause you a lot of frustration. There is a reason why general relativity is not taught before the second year. PointedEars -- Q: Who's on the case when the electricity goes out? A: Sherlock Ohms. (from: WolframAlpha)
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| From | gehan.ameresekere@gmail.com |
|---|---|
| Date | 2017-09-27 17:39 -0700 |
| Message-ID | <77e08c02-9060-4c73-b5cb-768a80f6f74b@googlegroups.com> |
| In reply to | #434158 |
On Thursday, September 28, 2017 at 2:51:25 AM UTC+5:30, Thomas 'PointedEars' Lahn wrote: > > True, but it would be a lot easier if you took the online course on > *special* relativity, *then* watched the lectures on *special* relativity, > *before* you watch these lectures on *general* relativity. > Posted wrong video I meant to post the on one SRT. Even I know the difference. What a lot of wasted ink.
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-28 02:52 +0200 |
| Message-ID | <1594923.TLkxdtWsSY@PointedEars.de> |
| In reply to | #434196 |
gehan.ameresekere@gmail.com wrote: > On Thursday, September 28, 2017 at 2:51:25 AM UTC+5:30, Thomas > 'PointedEars' Lahn wrote: >> True, but it would be a lot easier if you took the online course on >> *special* relativity, *then* watched the lectures on *special* >> relativity, *before* you watch these lectures on *general* relativity. > > Posted wrong video I meant to post the on one SRT. Even I know the > difference. What a lot of wasted ink. Wasted only because of your close-minded attitude. Even with special relativity what I said holds. Put simply, you are trying to learn university-level SR *evidently* before you have learned highschool- level SR. Well, good luck with that, you are going to need it. Score adjusted PointedEars -- Q: What did the nuclear physicist post on the laboratory door when he went camping? A: 'Gone fission'. (from: WolframAlpha)
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| From | Poutnik <poutnik@privacy.net> |
|---|---|
| Date | 2017-09-20 10:48 +0200 |
| Message-ID | <opta10$31p$1@dont-email.me> |
| In reply to | #432997 |
Dne 20.9.2017 v 09:34 gehan.ameresekere@gmail.com napsal(a): > On Wednesday, September 20, 2017 at 12:03:35 PM UTC+5:30, Poutnik wrote: >> / >> The purpose of gedankens from the train gedanken class >> is to illustrate consequence >> of the invariant vacuum light speed for simultaneity. >> >> Both ballistic and stationary aether theories >> operate with variable light speed, >> what exclude them from the gedanken >> and by evidence also as theories. >> > > First, some quotes on the Ether. > https://en.wikipedia.org/wiki/Aether_theories Stationary aether theory is quite distinguished form other aether theories and is not compatible with invariant light speed. > > Secondly, I am not saying there is an Ether, only stating that the results are the same as if there were an Ether in the train platform. > And that statement is false. As unless you mean Lorentz aether theory, the speed of light in these theories depends on the motion of reference frame wrt the rest frame of aether. -- Poutnik ( The Pilgrim, Der Wanderer ) A wise man guards words he says, as they say about him more, than he says about the subject.
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| From | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| Date | 2017-09-20 15:13 +0200 |
| Message-ID | <optphl$k0v$1@news.albasani.net> |
| In reply to | #432988 |
Den 20.09.2017 07.40, skrev gehan.ameresekere@gmail.com:
> On Tuesday, September 19, 2017 at 6:27:06 PM UTC+5:30, Paul B. Andersen wrote:
>> Here is a variant of Einstein's 'train gedanken'.
>>
>
> Thank you
>
>> Consider the following thought experiment.
>> Note what is given, and what is NOT given.
>>
>> Can you answer the questions?
>>
>> The given scenario:
>> - A train is moving at some speed along the railway.
>> - Paul is in the middle of the train.
>> - Ralph is standing close by the railway.
>> - At some time, a lightening bolt hits the front
>> end of the train, leaving a mark at the ground.
>> - At some time, a lightening bolt hits the aft
>> end of the train, leaving a mark at the ground.
>>
>>>>>> direction
> BACK FRONT
> [___________________PAUL_________________]*
>
> ________________________RALPH_________________*________
>
>
>> - At some time, a lightening bolt hits the aft
>> end of the train, leaving a mark at the ground.
>
>
>>>>>> direction
> BACK FRONT
> *[___________________PAUL__________*'______]*
>
> ___________*____________RALPH_________________*________
>
>
>
>> The observations:
>> - At some time, Paul passes Ralph.
>> - At some later time, Ralph sees the flashes
>> from the lightening bolts simultaneously.
>
> ok
>
>> - At some time, Paul sees the flash from the front,
>> and shortly later, he sees the flash from the aft end.
>> - Ralph finds that he is midway between the marks in the ground.
>>
>> The above are given facts, and can not be disputed.
>> The scenario and observations are obviously possible
>> in the real world.
>>
>
> We cannot proceed further without the following qualifications:
>
> Is the above scenario what we would expect if
>
> 1) Light transmission was through an Ether which was stationary in Ralph's frame?
>
> 2) Light transmission takes place through ballistic emission ? If yes, then why does one set of photons choose to hit Paul on the train first?
See below
>
>> Comment --------------------------------------
>> | The only condition for the observations to be
>> | possible in the real world is that the speed of
>> | light is finite. So Newton, Michelson, Lorentz,
>> | Ritz, Einstein and any other sane person accepting
>> | that the speed of light is finite would
>> | accept that the described observations are
>> | possible. They do not depend on any specific
>> | theory of physics.
>> -----------------------------------------------
>>
> See above.
See below.
>
>> Now the question is what conclusions we can
>> draw from the thought experiment.
>>
>> Comment --------------------------------------
>> | The interpretation of the observations is
>> | dependent of what assumptions are made
>> | for the propagation of light. So different
>> | theories of physics will give different
>> | conclusions for what the observations imply.
>> ----------------------------------------------
>>
>> Version #1
>> ----------
>> Assumptions:
>> Assume Galilean relativity, and that the speed
>> of light is c relative to Ralph.
The stated assumptions would be relevant
in theories like 'Michelson type' ether
theories where the ether is stationary
in Ralph's rest frame, and ballistic
theories where the light sources are considered
to be stationary in Ralph's rest frame.
>> Question #1:
>> What must Ralph and Paul conclude about
>> the temporal sequence of the lightening bolts?
>> Paul and Ralph may exchange information about
>> their observations before they draw their conclusions.
>>
>
> Ralph and Paul know what we know, that one sees the bolts because one is closer to the bolts than the other.
Answer to question #1
----------------------
Since Ralph observes the flashes simultaneously,
he is midway between the sources, and the speed
of light is isotropic in his frame, he can only
conclude that the lightening bolts struck simultaneously.
Since Paul's observations are qualitative only,
he can't conclude anything from his own observations
alone, but by conferring with Ralph he sees no reason
to disagree with Ralph. If the lightening bolts struck
simultaneously, he would see the the light from the front
first since the light from the front would move faster
relative to him than the light from the back.
Conclusion:
Ralph and Paul agree that the lightening bolts
struck simultaneously.
>
>> Version #2
>> ----------
>> Assumptions:
>> Assume Galilean relativity, and that the speed
>> of light is c relative to Paul.
The stated assumptions would be relevant for
the same theories as Version #1, with the difference
that the ether or the light sources would have to
be considered stationary in Paul's rest frame.
>> Question #2:
>> What must Ralph and Paul conclude about
>> the temporal sequence of the lightening bolts?
>> Paul and Ralph may exchange information about
>> their observations before they draw their conclusions.
>
> Simultaneous and c+v c-v for Ralph
Answer to question #2
----------------------
Since the speed of light is isotropic in Paul's frame,
he is in the middle of the train, and he saw the light
from the front first, he can only conclude that
the front lightening bolt struck before the aft one.
Since the light from the front moves slower
relative to Ralph than the light from the back,
he is midway between the sources, and he saw
the flashes simultaneously, Ralph can only
conclude that the front lightening bolt struck
before the aft one.
Conclusion:
Ralph and Paul agree that the front lightening bolt
struck before the aft lightening bolt.
>>
>> Version #3
>> ----------
>> Assumptions:
>> Assume that the speed of light is invariant
>> (the same in all inertial frames).
The stated assumptions are relevant in SR and LET.
> I cannot comment on invariance apart from the above two light emission theories.
>
>> Question #3:
>> What must Ralph and Paul conclude about
>> the temporal sequence of the lightening bolts?
Answer to question #3:
----------------------
Since Ralph observes the flashes simultaneously,
he is midway between the sources, and the speed
of light is isotropic in his frame, he can only
conclude that the lightening bolts struck simultaneously.
Since the speed of light is isotropic in Paul's frame,
he is in the middle of the train and he saw the light
from the front first, he can only conclude that
the front lightening bolt struck before the aft one.
Conclusion:
Ralph and Paul disagree, Ralph claims the lightening
bolts struck simultaneously, Paul claims the front one
struck before the aft one.
By conferring with each other, they conclude that
the temporal sequence of the lightening bolts must
be frame dependent.
>>
>> Question #4
>> What does the thought experiment prove about
>> the relativity of simultaneity?
>>
> That a stationary ether theory in the platform frame give the same results as Einstein predicted.
Answer to question #4
=====================
The thought experiment proves nothing about
whether or not simultaneity is relative in
the real world. No thought experiment can
ever prove anything about the real world.
What the thought experiment does prove, however,
is that the relativity of simultaneity is an
inevitable consequence of the postulates of SR.
If the speed of light is invariant, simultaneity
must be frame dependent.
And this is all a thought experiment can ever do:
demonstrate the consequences of a set of assumptions.
Last comments:
==============
Most readers will know that this thought experiment
is a slightly altered version of Einstein's
thought experiment in his popular book "Relativity".
Some of the reactions to this has always puzzled me.
Some cranks seem to believe that Einstein's thought
experiment is supposed to prove the validity of SR.
('validity' as in accordance with reality.)
And some cranks even dispute the possibility of
the observations made by the observers in his
thought experiment!
--
Paul
https://paulba.no/
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| From | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| Date | 2017-09-20 20:19 +0200 |
| Message-ID | <opubet$eig$1@news.albasani.net> |
| In reply to | #432886 |
Den 19.09.2017 14.56, skrev Paul B. Andersen:
> Here is a variant of Einstein's 'train gedanken'.
>
> Consider the following thought experiment.
> Note what is given, and what is NOT given.
>
> Can you answer the questions?
>
> The given scenario:
> - A train is moving at some speed along the railway.
> - Paul is in the middle of the train.
> - Ralph is standing close by the railway.
> - At some time, a lightening bolt hits the front
> end of the train, leaving a mark at the ground.
> - At some time, a lightening bolt hits the aft
> end of the train, leaving a mark at the ground.
>
> The observations:
> - At some time, Paul passes Ralph.
> - At some later time, Ralph sees the flashes
> from the lightening bolts simultaneously.
> - At some time, Paul sees the flash from the front,
> and shortly later, he sees the flash from the aft end.
> - Ralph finds that he is midway between the marks in the ground.
>
> The above are given facts, and can not be disputed.
> The scenario and observations are obviously possible
> in the real world.
>
> Comment --------------------------------------
> | The only condition for the observations to be
> | possible in the real world is that the speed of
> | light is finite. So Newton, Michelson, Lorentz,
> | Ritz, Einstein and any other sane person accepting
> | that the speed of light is finite would
> | accept that the described observations are
> | possible. They do not depend on any specific
> | theory of physics.
> -----------------------------------------------
>
> Now the question is what conclusions we can
> draw from the thought experiment.
>
> Comment --------------------------------------
> | The interpretation of the observations is
> | dependent of what assumptions are made
> | for the propagation of light. So different
> | theories of physics will give different
> | conclusions for what the observations imply.
> ----------------------------------------------
>
> Version #1
> ----------
> Assumptions:
> Assume Galilean relativity, and that the speed
> of light is c relative to Ralph.
> Question #1:
> What must Ralph and Paul conclude about
> the temporal sequence of the lightening bolts?
> Paul and Ralph may exchange information about
> their observations before they draw their conclusions.
>
> Version #2
> ----------
> Assumptions:
> Assume Galilean relativity, and that the speed
> of light is c relative to Paul.
> Question #2:
> What must Ralph and Paul conclude about
> the temporal sequence of the lightening bolts?
> Paul and Ralph may exchange information about
> their observations before they draw their conclusions.
>
> Version #3
> ----------
> Assumptions:
> Assume that the speed of light is invariant
> (the same in all inertial frames).
> Question #3:
> What must Ralph and Paul conclude about
> the temporal sequence of the lightening bolts?
>
> Question #4
> What does the thought experiment prove about
> the relativity of simultaneity?
>
>
The answers:
================
Version #1
----------
The stated assumptions would be relevant
in theories like 'Michelson type' ether
theories where the ether is stationary
in Ralph's rest frame, and ballistic
theories where the light sources are considered
to be stationary in Ralph's rest frame.
Answer to question #1
----------------------
Since Ralph observes the flashes simultaneously,
he is midway between the sources, and the speed
of light is isotropic in his frame, he can only
conclude that the lightening bolts struck simultaneously.
Since Paul's observations are qualitative only,
he can't conclude anything from his own observations
alone, but by conferring with Ralph he sees no reason
to disagree with Ralph. If the lightening bolts struck
simultaneously, he would see the the light from the front
first since the light from the front would move faster
relative to him than the light from the back.
Conclusion:
Ralph and Paul agree that the lightening bolts
struck simultaneously.
Version #2
-----------
The stated assumptions would be relevant for
the same theories as Version #1, with the difference
that the ether or the light sources would have to
be considered stationary in Paul's rest frame.
Answer to question #2
----------------------
Since the speed of light is isotropic in Paul's frame,
he is in the middle of the train, and he saw the light
from the front first, he can only conclude that
the front lightening bolt struck before the aft one.
Since the light from the front moves slower
relative to Ralph than the light from the back,
he is midway between the sources, and he saw
the flashes simultaneously, Ralph can only
conclude that the front lightening bolt struck
before the aft one.
Conclusion:
Ralph and Paul agree that the front lightening bolt
struck before the aft lightening bolt.
Version #3
----------
The stated assumptions are relevant in SR and LET.
Answer to question #3:
----------------------
Since Ralph observes the flashes simultaneously,
he is midway between the sources, and the speed
of light is isotropic in his frame, he can only
conclude that the lightening bolts struck simultaneously.
Since the speed of light is isotropic in Paul's frame,
he is in the middle of the train and he saw the light
from the front first, he can only conclude that
the front lightening bolt struck before the aft one.
Conclusion:
Ralph and Paul disagree, Ralph claims the lightening
bolts struck simultaneously, Paul claims the front one
struck before the aft one.
By conferring with each other, they conclude that
the temporal sequence of the lightening bolts must
be frame dependent.
Answer to question #4
=====================
The thought experiment proves nothing about
whether or not simultaneity is relative in
the real world. No thought experiment can
ever prove anything about the real world.
What the thought experiment does prove, however,
is that the relativity of simultaneity is an
inevitable consequence of the postulates of SR.
If the speed of light is invariant, simultaneity
must be frame dependent.
And this is all a thought experiment can ever do:
demonstrate the consequences of a set of assumptions.
Last comments:
==============
Most readers will know that this thought experiment
is a slightly altered version of Einstein's
thought experiment in his popular book "Relativity".
Some of the reactions to this has always puzzled me.
Some cranks seem to believe that Einstein's thought
experiment is supposed to prove the validity of SR.
('validity' as in not falsified by experiment.)
Some cranks even dispute the possibility of
the observations made by the observers in his
thought experiment!
--
Paul
https://paulba.no/
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| From | Kos Etrakis <uar@ksskkwi.ck> |
|---|---|
| Date | 2017-09-20 20:02 +0000 |
| Message-ID | <opuhg5$1k7n$5@gioia.aioe.org> |
| In reply to | #433064 |
Paul B. Andersen wrote: > Some cranks even dispute the possibility of the observations made by the > observers in his thought experiment! No, just you, a crank of the extreme kind.
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-21 09:10 +1000 |
| Message-ID | <opushd$7ji$1@gioia.aioe.org> |
| In reply to | #433064 |
On 21/09/17 04:19, Paul B. Andersen wrote:
> Den 19.09.2017 14.56, skrev Paul B. Andersen:
>
> Last comments:
> ==============
> Most readers will know that this thought experiment
> is a slightly altered version of Einstein's
> thought experiment in his popular book "Relativity".
>
> Some of the reactions to this has always puzzled me.
>
> Some cranks seem to believe that Einstein's thought
> experiment is supposed to prove the validity of SR.
> ('validity' as in not falsified by experiment.)
>
> Some cranks even dispute the possibility of
> the observations made by the observers in his
> thought experiment!
HAHAHHHAHHAHHAHHA! It seems Paul has suddenly realised that Ken Seto has thoroughly squashed the whole of SR with his
brilliant logic.
We know who the real cranks are now....The perpetrators of the Grand Conspiracy. 112 years of absolute crap has
stagnated physics....
--
HGW
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| From | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| Date | 2017-09-21 12:46 +0200 |
| Message-ID | <oq059u$p4h$1@news.albasani.net> |
| In reply to | #433118 |
Den 21.09.2017 01.10, skrev HGW:
> On 21/09/17 04:19, Paul B. Andersen wrote:
>> Den 19.09.2017 14.56, skrev Paul B. Andersen:
>
>>
>> Last comments:
>> ==============
>> Most readers will know that this thought experiment
>> is a slightly altered version of Einstein's
>> thought experiment in his popular book "Relativity".
>>
>> Some of the reactions to this has always puzzled me.
>>
>> Some cranks seem to believe that Einstein's thought
>> experiment is supposed to prove the validity of SR.
>> ('validity' as in not falsified by experiment.)
>>
>> Some cranks even dispute the possibility of
>> the observations made by the observers in his
>> thought experiment!
>
> HAHAHHHAHHAHHAHHA! It seems Paul has suddenly realised that Ken Seto has
> thoroughly squashed the whole of SR with his brilliant logic.
> We know who the real cranks are now....The perpetrators of the Grand
> Conspiracy. 112 years of absolute crap has stagnated physics....
>
>
Thanks for confirming my words. :-D
--
Paul
https://paulba.no/
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| From | kenseto <setoken@att.net> |
|---|---|
| Date | 2017-09-20 13:14 -0700 |
| Message-ID | <fdf54934-de56-4007-b88a-3f3cb04714d4@googlegroups.com> |
| In reply to | #432886 |
On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote: > Here is a variant of Einstein's 'train gedanken'. > > Consider the following thought experiment. > Note what is given, and what is NOT given. > > Can you answer the questions? > > The given scenario: > - A train is moving at some speed along the railway. > - Paul is in the middle of the train. > - Ralph is standing close by the railway. > - At some time, a lightening bolt hits the front > end of the train, leaving a mark at the ground. > - At some time, a lightening bolt hits the aft > end of the train, leaving a mark at the ground. > > The observations: > - At some time, Paul passes Ralph. > - At some later time, Ralph sees the flashes > from the lightening bolts simultaneously. > - At some time, Paul sees the flash from the front, > and shortly later, he sees the flash from the aft end. > - Ralph finds that he is midway between the marks in the ground. > > The above are given facts, and can not be disputed. > The scenario and observations are obviously possible > in the real world. No these are not facts, because you already assumed RoS. You assumed Paul is moving wrt the light fronts and that’s why Paul sees the light fronts from the front of the train before the light front from the rear of the train. The point is you can’t assume that Paul is moving wrt the light fronts to get RoS. Why? because there is no such thing as closing speed between Paul and the light fronts. Ralph is in the midpoint between the marks and thus he is in a position to determine that the strikes were simultaneous. After he made such determination he can use the LT to inform Paul that the strikes were simultaneous. > > Comment -------------------------------------- > | The only condition for the observations to be > | possible in the real world is that the speed of > | light is finite. So Newton, Michelson, Lorentz, > | Ritz, Einstein and any other sane person accepting > | that the speed of light is finite would > | accept that the described observations are > | possible. They do not depend on any specific > | theory of physics. > ----------------------------------------------- > > Now the question is what conclusions we can > draw from the thought experiment. > > Comment -------------------------------------- > | The interpretation of the observations is > | dependent of what assumptions are made > | for the propagation of light. So different > | theories of physics will give different > | conclusions for what the observations imply. > ---------------------------------------------- > > Version #1 > ---------- > Assumptions: > Assume Galilean relativity, and that the speed > of light is c relative to Ralph. > Question #1: > What must Ralph and Paul conclude about > the temporal sequence of the lightening bolts? > Paul and Ralph may exchange information about > their observations before they draw their conclusions. > > Version #2 > ---------- > Assumptions: > Assume Galilean relativity, and that the speed > of light is c relative to Paul. > Question #2: > What must Ralph and Paul conclude about > the temporal sequence of the lightening bolts? > Paul and Ralph may exchange information about > their observations before they draw their conclusions. > > Version #3 > ---------- > Assumptions: > Assume that the speed of light is invariant > (the same in all inertial frames). > Question #3: > What must Ralph and Paul conclude about > the temporal sequence of the lightening bolts? > > Question #4 > What does the thought experiment prove about > the relativity of simultaneity? > > > -- > Paul > > https://paulba.no/
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| From | mitchrae3323@gmail.com |
|---|---|
| Date | 2017-09-20 13:27 -0700 |
| Message-ID | <f79c44e1-5356-4c58-9b90-dcf52706b073@googlegroups.com> |
| In reply to | #433088 |
On Wednesday, September 20, 2017 at 1:14:42 PM UTC-7, kenseto wrote: > On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote: > > Here is a variant of Einstein's 'train gedanken'. > > > > Consider the following thought experiment. > > Note what is given, and what is NOT given. > > > > Can you answer the questions? > > > > The given scenario: > > - A train is moving at some speed along the railway. > > - Paul is in the middle of the train. > > - Ralph is standing close by the railway. > > - At some time, a lightening bolt hits the front > > end of the train, leaving a mark at the ground. > > - At some time, a lightening bolt hits the aft > > end of the train, leaving a mark at the ground. > > > > The observations: > > - At some time, Paul passes Ralph. > > - At some later time, Ralph sees the flashes > > from the lightening bolts simultaneously. > > - At some time, Paul sees the flash from the front, > > and shortly later, he sees the flash from the aft end. > > - Ralph finds that he is midway between the marks in the ground. > > > > The above are given facts, and can not be disputed. > > The scenario and observations are obviously possible > > in the real world. > > No these are not facts, because you already assumed RoS. You assumed Paul is moving wrt the light fronts and that’s why Paul sees the light fronts from the front of the train before the light front from the rear of the train. The point is you can’t assume that Paul is moving wrt the light fronts to get RoS. Why? because there is no such thing as closing speed between Paul and the light fronts. > > Ralph is in the midpoint between the marks and thus he is in a position to determine that the strikes were simultaneous. After he made such determination he can use the LT to inform Paul that the strikes were simultaneous. > > > > > Comment -------------------------------------- > > | The only condition for the observations to be > > | possible in the real world is that the speed of > > | light is finite. So Newton, Michelson, Lorentz, > > | Ritz, Einstein and any other sane person accepting > > | that the speed of light is finite would > > | accept that the described observations are > > | possible. They do not depend on any specific > > | theory of physics. > > ----------------------------------------------- > > > > Now the question is what conclusions we can > > draw from the thought experiment. > > > > Comment -------------------------------------- > > | The interpretation of the observations is > > | dependent of what assumptions are made > > | for the propagation of light. So different > > | theories of physics will give different > > | conclusions for what the observations imply. > > ---------------------------------------------- > > > > Version #1 > > ---------- > > Assumptions: > > Assume Galilean relativity, and that the speed > > of light is c relative to Ralph. > > Question #1: > > What must Ralph and Paul conclude about > > the temporal sequence of the lightening bolts? > > Paul and Ralph may exchange information about > > their observations before they draw their conclusions. > > > > Version #2 > > ---------- > > Assumptions: > > Assume Galilean relativity, and that the speed > > of light is c relative to Paul. > > Question #2: > > What must Ralph and Paul conclude about > > the temporal sequence of the lightening bolts? > > Paul and Ralph may exchange information about > > their observations before they draw their conclusions. > > > > Version #3 > > ---------- > > Assumptions: > > Assume that the speed of light is invariant > > (the same in all inertial frames). > > Question #3: > > What must Ralph and Paul conclude about > > the temporal sequence of the lightening bolts? > > > > Question #4 > > What does the thought experiment prove about > > the relativity of simultaneity? > > > > > > -- > > Paul > > > > https://paulba.no/ Where does the train begin to shrink? Mitchell Raemsch
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-21 09:29 +1000 |
| Message-ID | <oputkf$8qp$1@gioia.aioe.org> |
| In reply to | #433088 |
On 21/09/17 06:14, kenseto wrote:
> On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote:
>> - At some later time, Ralph sees the flashes from the lightening bolts simultaneously. - At some time, Paul sees
>> the flash from the front, and shortly later, he sees the flash from the aft end. - Ralph finds that he is midway
>> between the marks in the ground.
>>
>> The above are given facts, and can not be disputed. The scenario and observations are obviously possible in the
>> real world.
>
> No these are not facts, because you already assumed RoS. You assumed Paul is moving wrt the light fronts and that’s
> why Paul sees the light fronts from the front of the train before the light front from the rear of the train. The
> point is you can’t assume that Paul is moving wrt the light fronts to get RoS. Why? because there is no such thing as
> closing speed between Paul and the light fronts.
That is probably not the best way to tell Paul. It's too hard for him. You have to explain as though to a little kid.
SR doesn't specifically say that the light received by both observers came from sources at rest with the ground. It says
the light might just as well have come from the ends of the train...in which case Paul MUST see them simultaneously
since he is in the middle....but he doesn't...and so the RoS and SR must be completely wrong.
>
> Ralph is in the midpoint between the marks and thus he is in a position to determine that the strikes were
> simultaneous. After he made such determination he can use the LT to inform Paul that the strikes were simultaneous.
The train experiment cannot make any sense unless the sources of the light from the flashes are specified. If that is
done, the whole idea says nothing about simultaneity at all.
HGW
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| From | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| Date | 2017-09-21 14:03 +0200 |
| Message-ID | <oq09pr$eed$1@news.albasani.net> |
| In reply to | #433088 |
Den 20.09.2017 22.14, skrev kenseto: > On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote: >> Here is a variant of Einstein's 'train gedanken'. >> >> Consider the following thought experiment. >> Note what is given, and what is NOT given. >> >> Can you answer the questions? >> >> The given scenario: >> - A train is moving at some speed along the railway. >> - Paul is in the middle of the train. >> - Ralph is standing close by the railway. >> - At some time, a lightening bolt hits the front >> end of the train, leaving a mark at the ground. >> - At some time, a lightening bolt hits the aft >> end of the train, leaving a mark at the ground. >> >> The observations: >> - At some time, Paul passes Ralph. >> - At some later time, Ralph sees the flashes >> from the lightening bolts simultaneously. >> - At some time, Paul sees the flash from the front, >> and shortly later, he sees the flash from the aft end. >> - Ralph finds that he is midway between the marks in the ground. >> >> The above are given facts, and can not be disputed. >> The scenario and observations are obviously possible >> in the real world. > > No these are not facts, because you already assumed RoS. >> >> Comment -------------------------------------- >> | The interpretation of the observations is >> | dependent of what assumptions are made >> | for the propagation of light. So different >> | theories of physics will give different >> | conclusions for what the observations imply. >> ---------------------------------------------- >> >> Version #1 >> ---------- >> Assumptions: >> Assume Galilean relativity, and that the speed >> of light is c relative to Ralph. >> Question #1: >> What must Ralph and Paul conclude about >> the temporal sequence of the lightening bolts? >> Paul and Ralph may exchange information about >> their observations before they draw their conclusions. Is the RoS assumed? >> >> Version #2 >> ---------- >> Assumptions: >> Assume Galilean relativity, and that the speed >> of light is c relative to Paul. >> Question #2: >> What must Ralph and Paul conclude about >> the temporal sequence of the lightening bolts? >> Paul and Ralph may exchange information about >> their observations before they draw their conclusions. Is the RoS assumed? >> >> Version #3 >> ---------- >> Assumptions: >> Assume that the speed of light is invariant >> (the same in all inertial frames). >> Question #3: >> What must Ralph and Paul conclude about >> the temporal sequence of the lightening bolts? >> >> Question #4 >> What does the thought experiment prove about >> the relativity of simultaneity? >> >> >> -- >> Paul >> >> https://paulba.no/ -- Paul https://paulba.no/
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| From | mlwozniak@wp.pl |
|---|---|
| Date | 2017-09-21 05:19 -0700 |
| Message-ID | <7e08c344-4705-4b83-93d3-e336e4d1ad79@googlegroups.com> |
| In reply to | #433165 |
W dniu czwartek, 21 września 2017 14:03:09 UTC+2 użytkownik Paul B. Andersen napisał: > Is the RoS assumed? Yes, poor idiot, it is assumed; you assumed it after your insane idiot guru.
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| From | Kos Etrakis <uar@ksskkwi.ck> |
|---|---|
| Date | 2017-09-21 12:42 +0000 |
| Message-ID | <oq0c47$dj2$1@gioia.aioe.org> |
| In reply to | #433165 |
Paul B. Andersen wrote: > Den 20.09.2017 22.14, skrev kenseto: >> On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen >> wrote: >>> Here is a variant of Einstein's 'train gedanken'. Only an idiot would use an usenet client in own language.
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| From | kenseto <setoken@att.net> |
|---|---|
| Date | 2017-09-21 07:24 -0700 |
| Message-ID | <370d9798-b787-41a6-b177-89622e9b157a@googlegroups.com> |
| In reply to | #433165 |
On Thursday, September 21, 2017 at 8:03:09 AM UTC-4, Paul B. Andersen wrote: > Den 20.09.2017 22.14, skrev kenseto: > > On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote: > >> Here is a variant of Einstein's 'train gedanken'. > >> > >> Consider the following thought experiment. > >> Note what is given, and what is NOT given. > >> > >> Can you answer the questions? > >> > >> The given scenario: > >> - A train is moving at some speed along the railway. > >> - Paul is in the middle of the train. > >> - Ralph is standing close by the railway. > >> - At some time, a lightening bolt hits the front > >> end of the train, leaving a mark at the ground. > >> - At some time, a lightening bolt hits the aft > >> end of the train, leaving a mark at the ground. > >> > >> The observations: > >> - At some time, Paul passes Ralph. > >> - At some later time, Ralph sees the flashes > >> from the lightening bolts simultaneously. > >> - At some time, Paul sees the flash from the front, > >> and shortly later, he sees the flash from the aft end. > >> - Ralph finds that he is midway between the marks in the ground. > >> > >> The above are given facts, and can not be disputed. > >> The scenario and observations are obviously possible > >> in the real world. > > > > No these are not facts, because you already assumed RoS. > >> > >> Comment -------------------------------------- > >> | The interpretation of the observations is > >> | dependent of what assumptions are made > >> | for the propagation of light. So different > >> | theories of physics will give different > >> | conclusions for what the observations imply. > >> ---------------------------------------------- > >> > >> Version #1 > >> ---------- > >> Assumptions: > >> Assume Galilean relativity, and that the speed > >> of light is c relative to Ralph. > >> Question #1: > >> What must Ralph and Paul conclude about > >> the temporal sequence of the lightening bolts? > >> Paul and Ralph may exchange information about > >> their observations before they draw their conclusions. > > Is the RoS assumed? Yes. You said: _____________________________________________________________________ Paul Anderson wrote: The observations: >> - At some time, Paul passes Ralph. >> - At some later time, Ralph sees the flashes >> from the lightening bolts simultaneously. >> - At some time, Paul sees the flash from the front, >> and shortly later, he sees the flash from the aft end. >> - Ralph finds that he is midway between the marks in the ground. ____________________________________________________________________________ Clearly, this says that Paul sees the flashes to be non-simultaneous and Ralph sees the flashes to be simultaneous. That by definition is RoS. In order for Paul to be qualified as an observer, the simultaneous flashes must be coming from the ends of the train and Paul is at the middle of the train. That’s why Einstein constructed his gedanken that the flashes occur simultaneously at the ends of the train and leave marks on the track when M and M’ are coincided wrt each other. > > >> > >> Version #2 > >> ---------- > >> Assumptions: > >> Assume Galilean relativity, and that the speed > >> of light is c relative to Paul. > >> Question #2: > >> What must Ralph and Paul conclude about > >> the temporal sequence of the lightening bolts? > >> Paul and Ralph may exchange information about > >> their observations before they draw their conclusions. > > Is the RoS assumed? > > >> > >> Version #3 > >> ---------- > >> Assumptions: > >> Assume that the speed of light is invariant > >> (the same in all inertial frames). > >> Question #3: > >> What must Ralph and Paul conclude about > >> the temporal sequence of the lightening bolts? > >> > >> Question #4 > >> What does the thought experiment prove about > >> the relativity of simultaneity? > >> > >> > >> -- > >> Paul > >> > >> https://paulba.no/ > > > -- > Paul > > https://paulba.no/
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| From | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| Date | 2017-09-21 22:16 +0200 |
| Message-ID | <oq16ms$bpu$1@news.albasani.net> |
| In reply to | #433184 |
Den 21.09.2017 16.24, skrev kenseto: > On Thursday, September 21, 2017 at 8:03:09 AM UTC-4, Paul B. Andersen wrote: >> Den 20.09.2017 22.14, skrev kenseto: >>> On Tuesday, September 19, 2017 at 8:57:06 AM UTC-4, Paul B. Andersen wrote: >>>> Here is a variant of Einstein's 'train gedanken'. >>>> >>>> Consider the following thought experiment. >>>> Note what is given, and what is NOT given. >>>> >>>> Can you answer the questions? >>>> >>>> The given scenario: >>>> - A train is moving at some speed along the railway. >>>> - Paul is in the middle of the train. >>>> - Ralph is standing close by the railway. >>>> - At some time, a lightening bolt hits the front >>>> end of the train, leaving a mark at the ground. >>>> - At some time, a lightening bolt hits the aft >>>> end of the train, leaving a mark at the ground. >>>> >>>> The observations: >>>> - At some time, Paul passes Ralph. >>>> - At some later time, Ralph sees the flashes >>>> from the lightening bolts simultaneously. >>>> - At some time, Paul sees the flash from the front, >>>> and shortly later, he sees the flash from the aft end. >>>> - Ralph finds that he is midway between the marks in the ground. >>>> >>>> The above are given facts, and can not be disputed. >>>> The scenario and observations are obviously possible >>>> in the real world. >>> >>> No these are not facts, because you already assumed RoS. >>>> >>>> Comment -------------------------------------- >>>> | The interpretation of the observations is >>>> | dependent of what assumptions are made >>>> | for the propagation of light. So different >>>> | theories of physics will give different >>>> | conclusions for what the observations imply. >>>> ---------------------------------------------- >>>> >>>> Version #1 >>>> ---------- >>>> Assumptions: >>>> Assume Galilean relativity, and that the speed >>>> of light is c relative to Ralph. >>>> Question #1: >>>> What must Ralph and Paul conclude about >>>> the temporal sequence of the lightening bolts? >>>> Paul and Ralph may exchange information about >>>> their observations before they draw their conclusions. >> >> Is the RoS assumed? Obviously not. Galilean relativity is assumed. That means that absolute simultaneity is assumed. > > Yes. You said: > _____________________________________________________________________ > Paul Anderson wrote: > The observations: >>> - At some time, Paul passes Ralph. >>> - At some later time, Ralph sees the flashes >>> from the lightening bolts simultaneously. >>> - At some time, Paul sees the flash from the front, >>> and shortly later, he sees the flash from the aft end. >>> - Ralph finds that he is midway between the marks in the ground. > ____________________________________________________________________________ > Clearly, this says that Paul sees the flashes to be non-simultaneous and Ralph sees the flashes to be simultaneous. That by definition is RoS. Not at all, Ken. To see one flash before the other doesn't necessarily imply that the flashes can't be simultaneous. Since Ralph observes the flashes simultaneously, he is midway between the sources, and the speed of light is isotropic in his frame, he can only conclude that the lightening bolts struck simultaneously. Since Paul's observations are qualitative only, he can't conclude anything from his own observations alone, but by conferring with Ralph he sees no reason to disagree with Ralph. If the lightening bolts struck simultaneously, he would see the the light from the front first since the light from the front would move faster (c+v) relative to him than the light from the back (c-v). Conclusion: Ralph and Paul agree that the lightening bolts struck simultaneously. >>>> >>>> Version #2 >>>> ---------- >>>> Assumptions: >>>> Assume Galilean relativity, and that the speed >>>> of light is c relative to Paul. >>>> Question #2: >>>> What must Ralph and Paul conclude about >>>> the temporal sequence of the lightening bolts? >>>> Paul and Ralph may exchange information about >>>> their observations before they draw their conclusions. >> >> Is the RoS assumed? Obviously not. Galilean relativity is assumed. That means that absolute simultaneity is assumed. Since the speed of light is isotropic in Paul's frame, he is in the middle of the train, and he saw the light from the front first, he can only conclude that the front lightening bolt struck before the aft one. Since the light from the front moves slower (c-v) relative to Ralph than the light from the back (c+v), he is midway between the sources, and he saw the flashes simultaneously, Ralph can only conclude that the front lightening bolt struck before the aft one. Conclusion: Ralph and Paul agree that the front lightening bolt struck before the aft lightening bolt. >>>> Version #3 >>>> ---------- >>>> Assumptions: >>>> Assume that the speed of light is invariant >>>> (the same in all inertial frames). Invariance of the speed of light is assumed. >>>> Question #3: >>>> What must Ralph and Paul conclude about >>>> the temporal sequence of the lightening bolts? Since Ralph observes the flashes simultaneously, he is midway between the sources, and the speed of light is isotropic in his frame, he can only conclude that the lightening bolts struck simultaneously. Since the speed of light is isotropic in Paul's frame, he is in the middle of the train and he saw the light from the front first, he can only conclude that the front lightening bolt struck before the aft one. Conclusion: Ralph and Paul disagree, Ralph claims the lightening bolts struck simultaneously, Paul claims the front one struck before the aft one. By conferring with each other, they conclude that the temporal sequence of the lightening bolts must be frame dependent. Relativity of simultaneity is an inevitable consequence of invariant speed of light. >>>> >>>> Question #4 >>>> What does the thought experiment prove about >>>> the relativity of simultaneity? The thought experiment proves nothing about whether or not simultaneity is relative in the real world. No thought experiment can ever prove anything about the real world. What the thought experiment does prove, however, is that the relativity of simultaneity is an inevitable consequence of the postulates of SR. If the speed of light is invariant, simultaneity must be frame dependent. And this is all a thought experiment can ever do: demonstrate the consequences of a set of assumptions. -- Paul https://paulba.no/
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